Since the second World War, technological advances have permitted the construction of precision, seeker guided munitions (PSGM) that are actively guided during flight to their intended target and thus have a high probability of kill (PK). The high PK and the relatively inexpensive costs of these munitions, especially as compared to potential targets, make them cost effective weapons systems. The high PK, mature, available manufacturing technology, comparatively modest purchase price, and ready availability, have resulted in a proliferation of PSGMs. A variety of these systems are built and marketed by a multitude of companies and countries. As older PSGMs become obsolete and are replaced by more sophisticated systems, a large secondary market filters these older munitions to less financially endowed countries and organizations. This proliferation has increased the hazards from these weapons, both to combatants and non-combatants, especially as these munitions are obtained by fanatic/terrorist countries and/or organizations.
A precision, seeker guided munition is any munition, free fall or propelled that can be guided to its target via an onboard seeker and control system. The PSGMs addressed here are those that are either guided autonomously, that is, have an onboard or integral seeker and electronics sophisticated enough to recognize a target by shape, energy emissions/reflectance, comparison to a reference or other means, or are guided remotely but with the controller receiving target information through an on-munition seeker. PSGMs are characterized by their high PK and extreme lethality. PSGMs are a major threat, in all are as of combat, land, air and afloat. Man portable, seeker guided precision anti-aircraft missiles have the potential to be a significant terrorist threat to civil aviation.
Defense strategies to counter PSGMs are as varied as the possible munition's targets. An obvious defense stratagem is camouflage or preventing detection. Camouflage is attempted through paints that change the visual or energy reflective/emissive characteristic of a potential targets or by nets or materials that physically screen the target. Additional defensive ploys include decoys, obscurants, shoot downs and maneuver. Decoys attempt to mislead a precision guided munition so that is misses the target (flares and chaff are excellent examples), obscurants (smoke) hide the target behind an aerosol particulant distribution through which the target cannot be identified and methods are being attempted to shoot down a precision guided weapon, physically by blast or kinetics (thus far unsuccessful due to the small size, high speed and short flight time), or to disable the precision guided munitions seeker by directed energy, typically laser, thus rendering the missile unable to track its intended target. Additionally, maneuver may be used if the target can perform vector or positional changes that exceed the PSGMs seekers ability to track or flight control system to compensate for to obtain a hit. Other methods described have varying degrees of success against different types of precision guided munitions. None is perfect, none works against all threats, and none works, singly or in combination, with a high degree of assurity to negate the threat of PSGMs.
PSGMs have several systems components in common. All PSGMs are minimally possessed of a seeker, a commanding system, a guidance system, a maneuvering (flight control) system and a warhead. In other words, precision guided munitions broadly encompasses everything from free fall bombs fitted with a seeker and flight control mechanism, artillery projectiles fitted with a seeker and fight control mechanism, to self propelled fire and forget anti-armor, anti-aircraft or anti-ship missiles. Analysis of these systems reveals that the common items are the seeker, command system, flight controls and warhead. Generally the warheads are fairly stable compounds that must be detonated by a specific firing impulse from a specific mechanism. Warheads are extremely difficult to detonate prematurely. The flight controls are mechanical devices or gas reaction jets that are controlled in a number of different ways depending upon the munition. They are robust mechanisms not easily disrupted by external influences. The command system is either an onboard system or a remote system connected through cables to the launching vehicle. Because of the wide variety of possible commanding sources, a single mechanism able to defeat several or all of the command system types if not considered practical. Practically all precision guided munitions contain a seeker that receives, then passes information to an onboard guidance system or to a remote system. The seeker on a precision guided munition may be tailored to any or several portions of the energy spectrum, however the point of similarity is that all seekers must receive energy to track their intended target. The energy reception portion of the seeker is a delicate and sensitive mechanism and is always protected by being located behind a window (faring, nose cone, glass, etc.) that is transparent to the energy frequency of interest. Disruption, degradation, elimination or overload of energy receipt by the seeker effectively binds the PSGM. A blind PSGMs probability of striking its intended target decreases as a function of the distance away from the target the munition is blinded, the dynamics of the atmosphere through which the munition is moving, the control laws governing the munitions flight path and the maneuverability and ability of the intended target to change location.
Defense against PSGMs may be achieved by blinding the inbound missile's seeker, or disabling/degrading the incoming missile seekers ability to differentiate or perceive its target. Blinding is achieved by inserting a shield such as an inert or incandescent cloud of material in front of and intersecting an inbound munitions flight path so that the energy transparency characteristics of the precision, seeker guided munition's seeker aperture or the total energy received by the seeker are changed when the PSGM views and/or transits the dispersed material cloud. Obviously the nose of the missile, containing the energy aperture or "window" as the foremost component, transits the shield first and will be impacted by whatever the shielding material consists of. During transit of the shield or cloud of material, the "window" on the nose of the missile, through which energy must pass to be received by the seeker, may be crazed, cracked, abraded and or coated to either scatter inbound energy so that target source is no longer discernible/identifiable, or energy receipt is sufficiently outside seeker parameters so that the received energy is beyond the seekers perception threshold.
The material of the shield may or may not have obscurant characteristics similar to that of well known and documented smoke (normally white phosphorous) or other obscurants. While the dispersed material may (though it does not have to) obscure the intend target, the purpose of the dispersed material is to change the energy reception of the threat PSGMs seeker so that the seeker is no longer able to maintain a track on the intended target. With smoke or obscurants, once the PSGM has transited the obscurant cloud, it is again able to reacquire and track a target.
It is, therefore, an object of the present invention to provide an anti-missile missile with means to render the guidance system of an incoming threat missile inoperative for performing the function of guiding the incoming missile to a predetermined target.
It is another object of the present invention to provide an anti-missile missile with such means for injecting a shield material into the path of the incoming threat missile which will destroy its guidance capabilities.
It is still another object of the present invention to provide such shield material in the form of a cloud which will effectively "blind" the optical components of its guidance system as the missile penetrates the cloud.
It is yet another object of the present invention to provide such shield material which serves to coat, craze, crack, erode the seeker aperture or overload the sensing capabilities of the seeker of a precision guided missile to a level outside the parameters of the missile's seeker ability to track.